Version of LockManager based on using named/row DB locks. More...

Inheritance diagram for DBLockManager:

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Collaboration diagram for DBLockManager:

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Public Member Functions
	__construct (array $config)
	Construct a new instance from configuration.

	__destruct ()
	Make sure remaining locks get cleared for sanity.

Public Member Functions inherited from LockManager
	lock (array $paths, $type=self::LOCK_EX, $timeout=0)
	Lock the resources at the given abstract paths.

	lockByType (array $pathsByType, $timeout=0)
	Lock the resources at the given abstract paths.

	unlock (array $paths, $type=self::LOCK_EX)
	Unlock the resources at the given abstract paths.

	unlockByType (array $pathsByType)
	Unlock the resources at the given abstract paths.

Protected Member Functions

cacheCheckFailures ( $lockDb)

Checks if the DB has not recently had connection/query errors.

cacheRecordFailure ( $lockDb)

Log a lock request failure to the cache.

doGetLocksOnServer ( $lockSrv, array $paths, $type)

freeLocksOnServer ( $lockSrv, array $pathsByType)

Get a connection to a lock server and release locks on $paths.Subclasses must effectively implement this or releaseAllLocks().

Parameters

string	$lockSrv
array	$pathsByType	Map of LockManager::LOCK_* constants to lists of paths

Returns: StatusValue

getConnection ( $lockDb)

Get (or reuse) a connection to a lock DB.

getLocksOnServer ( $lockSrv, array $pathsByType)

getMissKey ( $lockDb)

Get a cache key for recent query misses for a DB.

initConnection ( $lockDb, IDatabase $db)

Do additional initialization for new lock DB connection.

isServerUp ( $lockSrv)

Protected Member Functions inherited from QuorumLockManager

collectPledgeQuorum ( $bucket, callable $callback)

Attempt to acquire pledges with the peers for a bucket.

doLock (array $paths, $type)

Lock resources with the given keys and lock type.

doLockByType (array $pathsByType)

doLockingRequestBucket ( $bucket, array $pathsByType)

Attempt to acquire locks with the peers for a bucket.

doUnlock (array $paths, $type)

Unlock resources with the given keys and lock type.

doUnlockByType (array $pathsByType)

doUnlockingRequestBucket ( $bucket, array $pathsByType)

Attempt to release locks with the peers for a bucket.

getBucketFromPath ( $path)

Get the bucket for resource path.

releaseAllLocks ()

Release all locks that this session is holding.

releasePledges ( $bucket, callable $callback)

Attempt to release pledges with the peers for a bucket.

Protected Member Functions inherited from LockManager

normalizePathsByType (array $pathsByType)

Normalize the $paths array by converting LOCK_UW locks into the appropriate type and removing any duplicated paths for each lock type.

sha1Base16Absolute ( $path)

Get the base 16 SHA-1 of a string, padded to 31 digits.

sha1Base36Absolute ( $path)

Get the base 36 SHA-1 of a string, padded to 31 digits.

Protected Attributes
IDatabase[]	$conns = []
	Map Database connections (DB name => Database)

array[] IDatabase[]	$dbServers
	Map of (DB names => server config or IDatabase)

	$lockExpiry

	$safeDelay

BagOStuff	$statusCache

Protected Attributes inherited from QuorumLockManager
array	$degradedBuckets = []
	Map of degraded buckets.

array	$srvsByBucket = []
	Map of bucket indexes to peer server lists.

Protected Attributes inherited from LockManager
	$domain

array	$locksHeld = []
	Map of (resource path => lock type => count)

	$lockTTL

array	$lockTypeMap
	Mapping of lock types to the type actually used.

LoggerInterface	$logger

string	$session
	Random 32-char hex number.

Additional Inherited Members
Public Attributes inherited from LockManager
const	LOCK_EX = 3

const	LOCK_SH = 1
	Lock types; stronger locks have higher values.

const	LOCK_UW = 2

Detailed Description

Version of LockManager based on using named/row DB locks.

This is meant for multi-wiki systems that may share files.

All lock requests for a resource, identified by a hash string, will map to one bucket. Each bucket maps to one or several peer DBs, each on their own server. A majority of peer DBs must agree for a lock to be acquired.

Caching is used to avoid hitting servers that are down.

Stability: stable: to extend

Since: 1.19

Definition at line 43 of file DBLockManager.php.

Constructor & Destructor Documentation

◆ __construct()

DBLockManager::__construct ( array $config )

Construct a new instance from configuration.

Stability: stable: to call

Parameters

array

$config

Parameters include:

dbServers : Associative array of DB names to server configuration. Configuration is an associative array that includes:
- host : DB server name
- dbname : DB name
- type : DB type (mysql,postgres,...)
- user : DB user
- password : DB user password
- tablePrefix : DB table prefix
- flags : DB flags; bitfield of IDatabase::DBO_* constants
dbsByBucket : Array of 1-16 consecutive integer keys, starting from 0, each having an odd-numbered list of DB names (peers) as values.
lockExpiry : Lock timeout (seconds) for dropped connections. [optional] This tells the DB server how long to wait before assuming connection failure and releasing all the locks for a session.
srvCache : A BagOStuff instance using APC or the like.

Reimplemented from LockManager.

Reimplemented in MySqlLockManager.

Definition at line 75 of file DBLockManager.php.

References $lockExpiry.

◆ __destruct()

DBLockManager::__destruct ( )

Make sure remaining locks get cleared for sanity.

Definition at line 231 of file DBLockManager.php.

References QuorumLockManager\releaseAllLocks().

Member Function Documentation

◆ cacheCheckFailures()

DBLockManager::cacheCheckFailures ( $lockDb )

protected

Checks if the DB has not recently had connection/query errors.

This just avoids wasting time on doomed connection attempts.

Parameters

string $lockDb

Returns: bool

Definition at line 200 of file DBLockManager.php.

References getMissKey().

Referenced by isServerUp().

◆ cacheRecordFailure()

DBLockManager::cacheRecordFailure ( $lockDb )

protected

Log a lock request failure to the cache.

Parameters

string $lockDb

Returns: bool Success

Definition at line 212 of file DBLockManager.php.

References getMissKey().

Referenced by isServerUp().

◆ doGetLocksOnServer()

DBLockManager::doGetLocksOnServer	(		$lockSrv,
		array	$paths,
			$type
	)

abstractprotected

Reimplemented in MySqlLockManager, and PostgreSqlLockManager.

Referenced by getLocksOnServer().

◆ freeLocksOnServer()

DBLockManager::freeLocksOnServer	(		$lockSrv,
		array	$pathsByType
	)

protected

Get a connection to a lock server and release locks on $paths.Subclasses must effectively implement this or releaseAllLocks().

Parameters

string	$lockSrv
array	$pathsByType	Map of LockManager::LOCK_* constants to lists of paths

Returns: StatusValue

Stability: stable: to override

Reimplemented from QuorumLockManager.

Definition at line 120 of file DBLockManager.php.

◆ getConnection()

DBLockManager::getConnection ( $lockDb )

protected

Get (or reuse) a connection to a lock DB.

Parameters

string $lockDb

Returns: IDatabase

Exceptions

DBError
UnexpectedValueException

Definition at line 152 of file DBLockManager.php.

References $lockExpiry, and initConnection().

Referenced by MySqlLockManager\doGetLocksOnServer(), PostgreSqlLockManager\doGetLocksOnServer(), and isServerUp().

◆ getLocksOnServer()

DBLockManager::getLocksOnServer	(		$lockSrv,
		array	$pathsByType
	)

protected

Todo:: change this code to work in one batch

Stability: stable: to override

Parameters

string	$lockSrv
array	$pathsByType

Returns: StatusValue

Reimplemented from QuorumLockManager.

Definition at line 105 of file DBLockManager.php.

References $type, and doGetLocksOnServer().

◆ getMissKey()

DBLockManager::getMissKey ( $lockDb )

protected

Get a cache key for recent query misses for a DB.

Parameters

string $lockDb

Returns: string

Definition at line 224 of file DBLockManager.php.

Referenced by cacheCheckFailures(), and cacheRecordFailure().

◆ initConnection()

DBLockManager::initConnection	(		$lockDb,
		IDatabase	$db
	)

protected

Do additional initialization for new lock DB connection.

Stability: stable: to override

Parameters

string	$lockDb
IDatabase	$db

Exceptions

DBError

Reimplemented in MySqlLockManager.

Definition at line 190 of file DBLockManager.php.

Referenced by getConnection().

◆ isServerUp()

DBLockManager::isServerUp ( $lockSrv )

protected

See also: QuorumLockManager::isServerUp()

Parameters

string $lockSrv

Returns: bool

Reimplemented from QuorumLockManager.

Definition at line 129 of file DBLockManager.php.

References cacheCheckFailures(), cacheRecordFailure(), and getConnection().

Member Data Documentation

◆ $conns

IDatabase [] DBLockManager::$conns = []

protected

Map Database connections (DB name => Database)

Definition at line 52 of file DBLockManager.php.

◆ $dbServers

array [] IDatabase [] DBLockManager::$dbServers

protected

Map of (DB names => server config or IDatabase)

Definition at line 45 of file DBLockManager.php.

◆ $lockExpiry

DBLockManager::$lockExpiry

protected

Definition at line 49 of file DBLockManager.php.

Referenced by __construct(), and getConnection().

◆ $safeDelay

DBLockManager::$safeDelay

protected

Definition at line 50 of file DBLockManager.php.

◆ $statusCache

BagOStuff DBLockManager::$statusCache

protected

Definition at line 47 of file DBLockManager.php.

The documentation for this class was generated from the following file:

includes/libs/lockmanager/DBLockManager.php

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ __construct()

◆ __destruct()

Member Function Documentation

◆ cacheCheckFailures()

◆ cacheRecordFailure()

◆ doGetLocksOnServer()

◆ freeLocksOnServer()

◆ getConnection()

◆ getLocksOnServer()

◆ getMissKey()

◆ initConnection()

◆ isServerUp()

Member Data Documentation

◆ $conns

◆ $dbServers

◆ $lockExpiry

◆ $safeDelay

◆ $statusCache